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Wetten PA, Arismendi Sosa AC, Mariani ML, Vargas PM, Michaut MA, Penissi AB. Dehydroleucodine and xanthatin, two natural anti-inflammatory lactones, inhibit mast cell degranulation by affecting the actin cytoskeleton. Cytoskeleton (Hoboken) 2024; 81:215-226. [PMID: 37929805 DOI: 10.1002/cm.21805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 10/16/2023] [Accepted: 10/22/2023] [Indexed: 11/07/2023]
Abstract
Actin remodeling is a critical regulator of mast cell secretion. In previous work, we have shown that dehydroleucodine and xanthatin, two natural α,β-unsaturated lactones, exhibit anti-inflammatory and mast cell stabilizing properties. Based on this background, this study aimed to determine whether the mast cell stabilizing action of these lactones is associated with changes in the actin cytoskeleton. Rat peritoneal mast cells were preincubated in the presence of dehydroleucodine or xanthatin before incubation with compound 48/80. Comparative studies with sodium cromoglycate and latrunculin B were also made. After treatments, different assays were performed on mast cell samples: β-hexosaminidase release, cell viability studies, quantification of mast cells and their state of degranulation by light microscopy, transmission electron microscopy, and actin staining for microscopy observation. Results showed that dehydroleucodine and xanthatin inhibited mast cell degranulation, evidenced by the inhibition of β-hexosaminidase release and decreased degranulated mast cell percentage. At the same time, both lactones altered the F-actin cytoskeleton in mast cells resulting, similarly to Latrunculin B, in a higher concentration of nuclear F-actin when activated by compound 48/80. For the first time, this study describes the biological properties of dehydroleucodine and xanthatin concerning to the rearrangement of actin filaments during stimulated exocytosis in mast cells. These data have important implications for developing new anti-inflammatory and mast cell stabilizing drugs and for designing new small molecules that may interact with the actin cytoskeleton.
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Affiliation(s)
- Paula A Wetten
- Instituto de Histología y Embriología "Dr. Mario H. Burgos" (IHEM), Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | | | - María Laura Mariani
- Instituto de Histología y Embriología "Dr. Mario H. Burgos" (IHEM), Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Patricia M Vargas
- Instituto de Histología y Embriología "Dr. Mario H. Burgos" (IHEM), Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Marcela Alejandra Michaut
- Instituto de Histología y Embriología "Dr. Mario H. Burgos" (IHEM), Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Alicia Beatriz Penissi
- Instituto de Histología y Embriología "Dr. Mario H. Burgos" (IHEM), Universidad Nacional de Cuyo-CONICET, Mendoza, Argentina
- Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
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2
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Imamura K, Tomita Y, Sato R, Ikeda T, Iyama S, Jodai T, Takahashi M, Takaki A, Akaike K, Hamada S, Sakata S, Saruwatari K, Saeki S, Ikeda K, Suzuki M, Sakagami T. Clinical Implications and Molecular Characterization of Drebrin-Positive, Tumor-Infiltrating Exhausted T Cells in Lung Cancer. Int J Mol Sci 2022; 23:ijms232213723. [PMID: 36430217 PMCID: PMC9694580 DOI: 10.3390/ijms232213723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/05/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022] Open
Abstract
T cells express an actin-binding protein, drebrin, which is recruited to the contact site between the T cells and antigen-presenting cells during the formation of immunological synapses. However, little is known about the clinical implications of drebrin-expressing, tumor-infiltrating lymphocytes (TILs). To address this issue, we evaluated 34 surgical specimens of pathological stage I-IIIA squamous cell lung cancer. The immune context of primary tumors was investigated using fluorescent multiplex immunohistochemistry. The high-speed scanning of whole-slide images was performed, and the tissue localization of TILs in the tumor cell nest and surrounding stroma was automatically profiled and quantified. Drebrin-expressing T cells were characterized using drebrin+ T cells induced in vitro and publicly available single-cell RNA sequence (scRNA-seq) database. Survival analysis using the propensity scores revealed that a high infiltration of drebrin+ TILs within the tumor cell nest was independently associated with short relapse-free survival and overall survival. Drebrin+ T cells induced in vitro co-expressed multiple exhaustion-associated molecules. The scRNA-seq analyses confirmed that the exhausted tumor-infiltrating CD8+ T cells specifically expressed drebrin. Our study suggests that drebrin-expressing T cells present an exhausted phenotype and that tumor-infiltrating drebrin+ T cells affect clinical outcomes in patients with resectable squamous cell lung cancer.
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Affiliation(s)
- Kosuke Imamura
- Department of Respiratory Medicine, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Yusuke Tomita
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
- Correspondence: ; Tel.: +81-96-373-5012; Fax: +81-96-373-5328
| | - Ryo Sato
- Laboratory of Stem Cell and Neuro-Vascular Biology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA
| | - Tokunori Ikeda
- Laboratory of Clinical Pharmacology and Therapeutics, Faculty of Pharmaceutical Sciences, Sojo University, 4-22-1, Ikeda Nishi-ku, Kumamoto-shi 860-0082, Kumamoto, Japan
| | - Shinji Iyama
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Takayuki Jodai
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Misako Takahashi
- Department of Respiratory Medicine, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Akira Takaki
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Kimitaka Akaike
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Shohei Hamada
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Shinya Sakata
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Koichi Saruwatari
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Sho Saeki
- Department of Respiratory Medicine, Kumamoto University Hospital, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Koei Ikeda
- Department of Thoracic and Breast Surgery, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Makoto Suzuki
- Department of Thoracic and Breast Surgery, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
| | - Takuro Sakagami
- Department of Respiratory Medicine, Faculty of Life Sciences, Kumamoto University, Honjo 1-1-1, Chuo-ku, Kumamoto-shi 860-8556, Kumamoto, Japan
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3
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Blank U, Huang H, Kawakami T. The high affinity IgE receptor: a signaling update. Curr Opin Immunol 2021; 72:51-58. [PMID: 33838574 DOI: 10.1016/j.coi.2021.03.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/22/2021] [Indexed: 01/01/2023]
Abstract
Here we update receptor proximal and distant signaling events of the mast cell high affinity IgE receptor (FcεRI) launching immediate type I hypersensitivity and an inflammatory cytokine-chemokine cascade. Different physiologic antigen concentrations, their affinity, and valency for the IgE ligand produce distinct intracellular signaling events with different outcomes. Investigating mast cell degranulation has revealed a complex molecular machinery that relays proximal signaling to cytoskeletal reorganization, granule transport and membrane fusion. Several new phosphorylation- and calcium-responsive effectors have been described. FcεRI signaling also promotes de novo gene transcription. Recent progress has identified enhancers at genes that are upregulated in mast cells after stimulation through FcεRI using next generation sequencing methods. Enhancers at genes that respond to antigenic stimulation in human mast cells revealed Ca2+-dependency. Stimulation-responsive super enhancers in mouse mast cells have also been identified. Mast cell lineage-determining transcription factor GATA2 primes these enhancers to respond to antigenic stimulation.
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Affiliation(s)
- Ulrich Blank
- Université de Paris, Centre de Recherche sur l'Inflammation, INSERM UMR1149, CNRS ERL8252, Faculté de Médecine site Bichat, Paris, France; Laboratoire d'Excellence Inflamex, Paris, France.
| | - Hua Huang
- Department of Immunology and Genomic Medicine, National Jewish Health, Denver, CO 80206, USA; Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Toshiaki Kawakami
- Laboratory of Allergic Diseases, Center for Autoimmunity and Inflammation, La Jolla Institute for Immunology, La Jolla, CA 92037, USA; Department of Dermatology, School of Medicine, University of California San Diego, La Jolla, CA 92093, USA
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Ménasché G, Longé C, Bratti M, Blank U. Cytoskeletal Transport, Reorganization, and Fusion Regulation in Mast Cell-Stimulus Secretion Coupling. Front Cell Dev Biol 2021; 9:652077. [PMID: 33796537 PMCID: PMC8007931 DOI: 10.3389/fcell.2021.652077] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/03/2021] [Indexed: 01/16/2023] Open
Abstract
Mast cells are well known for their role in allergies and many chronic inflammatory diseases. They release upon stimulation, e.g., via the IgE receptor, numerous bioactive compounds from cytoplasmic secretory granules. The regulation of granule secretion and its interaction with the cytoskeleton and transport mechanisms has only recently begun to be understood. These studies have provided new insight into the interaction between the secretory machinery and cytoskeletal elements in the regulation of the degranulation process. They suggest a tight coupling of these two systems, implying a series of specific signaling effectors and adaptor molecules. Here we review recent knowledge describing the signaling events regulating cytoskeletal reorganization and secretory granule transport machinery in conjunction with the membrane fusion machinery that occur during mast cell degranulation. The new insight into MC biology offers novel strategies to treat human allergic and inflammatory diseases targeting the late steps that affect harmful release from granular stores leaving regulatory cytokine secretion intact.
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Affiliation(s)
- Gaël Ménasché
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Cyril Longé
- Laboratory of Molecular Basis of Altered Immune Homeostasis, Imagine Institute, INSERM UMR 1163, Université de Paris, Paris, France
| | - Manuela Bratti
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
| | - Ulrich Blank
- Centre de Recherche sur l'Inflammation, INSERM UMR 1149, CNRS ERL8252, Faculté de Médecine site Bichat, Université de Paris, Paris, France.,Laboratoire d'Excellence Inflamex, Université de Paris, Paris, France
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5
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Draberova L, Draberova H, Potuckova L, Halova I, Bambouskova M, Mohandas N, Draber P. Cytoskeletal Protein 4.1R Is a Positive Regulator of the FcεRI Signaling and Chemotaxis in Mast Cells. Front Immunol 2020; 10:3068. [PMID: 31993060 PMCID: PMC6970983 DOI: 10.3389/fimmu.2019.03068] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022] Open
Abstract
Protein 4.1R, a member of the 4.1 family, functions as a bridge between cytoskeletal and plasma membrane proteins. It is expressed in T cells, where it binds to a linker for activation of T cell (LAT) family member 1 and inhibits its phosphorylation and downstream signaling events after T cell receptor triggering. The role of the 4.1R protein in cell activation through other immunoreceptors is not known. In this study, we used 4.1R-deficient (4.1R-KO) and 4.1R wild-type (WT) mice and explored the role of the 4.1R protein in the high-affinity IgE receptor (FcεRI) signaling in mast cells. We found that bone marrow mast cells (BMMCs) derived from 4.1R-KO mice showed normal growth in vitro and expressed FcεRI and c-KIT at levels comparable to WT cells. However, 4.1R-KO cells exhibited reduced antigen-induced degranulation, calcium response, and secretion of tumor necrosis factor-α. Chemotaxis toward antigen and stem cell factor (SCF) and spreading on fibronectin were also reduced in 4.1R-KO BMMCs, whereas prostaglandin E2-mediated chemotaxis was not affected. Antibody-induced aggregation of tetraspanin CD9 inhibited chemotaxis toward antigen in WT but not 4.1R-KO BMMCs, implying a CD9-4.1R protein cross-talk. Further studies documented that in the absence of 4.1R, antigen-mediated phosphorylation of FcεRI β and γ subunits was not affected, but phosphorylation of SYK and subsequent signaling events such as phosphorylation of LAT1, phospholipase Cγ1, phosphatases (SHP1 and SHIP), MAP family kinases (p38, ERK, JNK), STAT5, CBL, and mTOR were reduced. Immunoprecipitation studies showed the presence of both LAT1 and LAT2 (LAT, family member 2) in 4.1R immunocomplexes. The positive regulatory role of 4.1R protein in FcεRI-triggered activation was supported by in vivo experiments in which 4.1R-KO mice showed the normal presence of mast cells in the ears and peritoneum, but exhibited impaired passive cutaneous anaphylaxis. The combined data indicate that the 4.1R protein functions as a positive regulator in the early activation events after FcεRI triggering in mast cells.
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Affiliation(s)
- Lubica Draberova
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Helena Draberova
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Lucie Potuckova
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Ivana Halova
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Monika Bambouskova
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | - Narla Mohandas
- Red Cell Physiology Laboratory, New York Blood Center, New York, NY, United States
| | - Petr Draber
- Department of Signal Transduction, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
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6
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Elizondo DM, Andargie TE, Haddock NL, Boddie TA, Lipscomb MW. Drebrin 1 in dendritic cells regulates phagocytosis and cell surface receptor expression through recycling for efficient antigen presentation. Immunology 2018; 156:136-146. [PMID: 30317558 DOI: 10.1111/imm.13010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 09/25/2018] [Accepted: 10/01/2018] [Indexed: 12/01/2022] Open
Abstract
Phagocytosis, macropinocytosis and antigen presentation by dendritic cells (DC) requires reorganization of the actin cytoskeleton. Drebrin (Dbn1) is an actin binding and stabilizing protein with roles in endocytosis, formation of dendrite spines in neurons and coordinating cell-cell synapses in immune cells. However, its role in DC phagocytosis and antigen presentation is unknown. These studies now report that silencing of Dbn1 in DC resulted in restrained cell surface display of receptors, most notably MHC class I and II and co-stimulatory molecules. This, as expected, resulted in impaired antigen-specific T-cell activation and proliferation. Studies additionally revealed that knockdown of Dbn1 in DC impaired macropinocytosis and phagocytosis. However, there was a concomitant increase in fluid-phase uptake, suggesting that Dbn1 is responsible for the differential control of macropinocytosis versus micropinocytosis activities. Taken together, these findings now reveal that Dbn1 plays a major role in coordinating the actin cytoskeletal activities responsible for antigen presentation in DC.
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Affiliation(s)
| | | | - Naomi L Haddock
- Department of Biology, Howard University, Washington, DC, USA
| | - Thomas A Boddie
- Department of Biology, Howard University, Washington, DC, USA
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7
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Drebrin in Neuronal Migration and Axonal Growth. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:141-155. [PMID: 28865019 DOI: 10.1007/978-4-431-56550-5_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
During development, production of neurons from neural stem cells, migration of neurons from their birthplace to their final location, and extension of neurites, axons, and dendrites are important for the formation of functional neuronal circuits. The actin cytoskeleton has major roles in the morphological development of neurons. In this chapter, we focused on the distribution and function of the actin-binding protein, drebrin, to elucidate the importance of drebrin-bound F-actin in neurons during early developmental stages of neurons in embryonic, postnatal, and adult brains. There are three major isoforms of drebrin in the chicken brain (E1, E2, and A) and two major isoforms in the mammalian brain (E and A). Among these drebrin isoforms, drebrin E1 and E2 in chicken and drebrin E in the mammalian brain are involved in these neuronal stages. In migrating neurons of the developing and adult brain, drebrin is localized at the base of filopodia of leading processes, to regulate neuronal migration. In axonal growth cones, drebrin is localized in the transitional zone to regulate axonal growth by inhibiting actomyosin interactions and mediating the interactions between F-actin and microtubules. For axonal collateral branching, drebrin is localized at axonal actin patches and the base of filopodia, to accelerate the transition from actin patches to filopodia and stabilize the filopodia.
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8
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Drebrin Regulation of Calcium Signaling in Immune Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017. [PMID: 28865026 DOI: 10.1007/978-4-431-56550-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Store-operated Ca2+ channels are plasma membrane channels that are activated by depletion of intracellular Ca2+ stores, resulting in an increase in intracellular Ca2+; however, little is known about their regulation. Our work has shown that the immunosuppressant compound BTP2, which blocks Ca2+ influx into cells, interacts with the actin-reorganizing protein, drebrin. Here we review the role of drebrin in the regulation of calcium signaling, with a focus on immune cells.
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Role of Drebrin at the Immunological Synapse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1006:271-280. [PMID: 28865025 DOI: 10.1007/978-4-431-56550-5_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Although drebrin was first described in neurons, it is also expressed in cells of the immune system, such as T lymphocytes and mast cells. Another member of the drebrin family of proteins, mammalian actin-binding protein 1 (mAbp-1) is more widely expressed and plays important roles in the function of macrophages, polymorphonuclear neutrophils, and B lymphocytes. We will briefly discuss on the function of mAbp-1 and drebrin in immune cells with emphasis on T cells. Specifically, drebrin enables the immune responses of CD4+ T lymphocytes. T cells are activated after the recognition of an antigen presented by antigen-presenting cells through cognate cell-cell contacts called immunological synapses (IS). In CD4+ T cells, drebrin associates with the chemokine receptor CXCR4, and both molecules redistribute to the IS displaying similar dynamics. Through its interaction with CXCR4 and the actin cytoskeleton, drebrin regulates T cell activation. CD4+ T cells are one of the main targets for the human immunodeficiency virus (HIV)-1. This virus utilizes the IS structure to be transmitted to uninfected cells, forming cell-cell contacts called virological synapses (VS). Interestingly, drebrin negatively regulates HIV-1 infection of CD4+ T lymphocytes, by regulating actin polymerization at the VS.
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Nager AR, Goldstein JS, Herranz-Pérez V, Portran D, Ye F, Garcia-Verdugo JM, Nachury MV. An Actin Network Dispatches Ciliary GPCRs into Extracellular Vesicles to Modulate Signaling. Cell 2016; 168:252-263.e14. [PMID: 28017328 DOI: 10.1016/j.cell.2016.11.036] [Citation(s) in RCA: 239] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 09/14/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022]
Abstract
Signaling receptors dynamically exit cilia upon activation of signaling pathways such as Hedgehog. Here, we find that when activated G protein-coupled receptors (GPCRs) fail to undergo BBSome-mediated retrieval from cilia back into the cell, these GPCRs concentrate into membranous buds at the tips of cilia before release into extracellular vesicles named ectosomes. Unexpectedly, actin and the actin regulators drebrin and myosin 6 mediate ectosome release from the tip of cilia. Mirroring signal-dependent retrieval, signal-dependent ectocytosis is a selective and effective process that removes activated signaling molecules from cilia. Congruently, ectocytosis compensates for BBSome defects as ectocytic removal of GPR161, a negative regulator of Hedgehog signaling, permits the appropriate transduction of Hedgehog signals in Bbs mutants. Finally, ciliary receptors that lack retrieval determinants such as the anorexigenic GPCR NPY2R undergo signal-dependent ectocytosis in wild-type cells. Our data show that signal-dependent ectocytosis regulates ciliary signaling in physiological and pathological contexts.
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Affiliation(s)
- Andrew R Nager
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Jaclyn S Goldstein
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Vicente Herranz-Pérez
- Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universitat de València, CIBERNED, 46980 Valencia, Spain; Unidad Mixta de Esclerosis Múltiple y Neurorregeneración, IIS Hospital La Fe-UVEG, 46026 Valencia, Spain
| | - Didier Portran
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Fan Ye
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA
| | - Jose Manuel Garcia-Verdugo
- Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universitat de València, CIBERNED, 46980 Valencia, Spain; Unidad Mixta de Esclerosis Múltiple y Neurorregeneración, IIS Hospital La Fe-UVEG, 46026 Valencia, Spain
| | - Maxence V Nachury
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305-5345, USA.
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Ang WG, Church AM, Kulis M, Choi HW, Burks AW, Abraham SN. Mast cell desensitization inhibits calcium flux and aberrantly remodels actin. J Clin Invest 2016; 126:4103-4118. [PMID: 27669462 PMCID: PMC5096925 DOI: 10.1172/jci87492] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/16/2016] [Indexed: 11/17/2022] Open
Abstract
Rush desensitization (DS) is a widely used and effective clinical strategy for the rapid inhibition of IgE-mediated anaphylactic responses. However, the cellular targets and underlying mechanisms behind this process remain unclear. Recent studies have implicated mast cells (MCs) as the primary target cells for DS. Here, we developed a murine model of passive anaphylaxis with demonstrated MC involvement and an in vitro assay to evaluate the effect of DS on MCs. In contrast with previous reports, we determined that functional IgE remains on the cell surface of desensitized MCs following DS. Despite notable reductions in MC degranulation following DS, the high-affinity IgE receptor FcεRI was still capable of transducing signals in desensitized MCs. Additionally, we found that displacement of the actin cytoskeleton and its continued association with FcεRI impede the capacity of desensitized MCs to evoke the calcium response that is essential for MC degranulation. Together, these findings suggest that reduced degranulation responses in desensitized MCs arise from aberrant actin remodeling, providing insights that may lead to improvement of DS treatments for anaphylactic responses.
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Affiliation(s)
- W.X. Gladys Ang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Alison M. Church
- GlaxoSmithKline, Rare Diseases Unit, Research Triangle Park, North Carolina, USA
| | - Mike Kulis
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - A. Wesley Burks
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Soman N. Abraham
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
- Department of Pathology and
- Department of Immunology, Duke University Medical Center, Durham, North Carolina, USA
- Program in Emerging Infectious Diseases, Duke–National University of Singapore, Singapore
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